Question

With a Newton's Cradle, apply the momentum formula to the outcome of actions if 1,2, 3, or 4 out of 5 are put into motion. Choose the mass and the velocity shall initially be 5 m/s in all examples.

Answer 1

The question states to choose a mass for each ball and you are given a velocity of 5m/s. Therefore, sum up the masses of each ball in motion and multiply that times the velocity of 5m/s to get the momentum for each situation (1, 2, 3, 4 or 5 balls in motion).
\[\rho = M_{total}v=M_{total}(5m/s)\]